Health of neonates born in the maternity hospital in Bern, Switzerland, 1880–1900 and 1914–1922

The identification of factors impeding normal fetal development and growth is crucial for improving neonatal health. Historical studies are relevant because they show which parameters have influenced neonatal health in the past in order to better understand the present. We studied temporal changes of neonatal health outcomes (birth weight, gestational age, stillbirth rate) and the influence of different cofactors in two time periods. Moreover, we investigated particularly neonatal health in the wake of the 1918/19 influenza pandemic. Data were transcribed from the Bern Maternity Hospital and consists of two time periods: A) The years 1880, 1885, 1890, 1895 and 1900 (N = 1530, births’ coverage 20%); B) The years 1914–1922 (N = 6924, births’ coverage 40–50%). Linear regression models were used to estimate the effect of birth year on birth weight, and logistic regression models to estimate the effect of birth year and of the exposure to the pandemic on premature birth, stillborn and low birth weight (LBW). Mean birth weight increased only minimally between the two datasets; whereas, in the years 1914–1922, the preterm birth and stillbirth rates were markedly reduced compared with the years 1880–1900. Sex, parity, gestational age and maternal age were significantly associated with birth weight in both time periods. The probability of LBW was significantly increased in 1918 (OR 1.49 (95% CI 1.00–2.23)) and in 1919 (OR 1.55 (95% CI 1.02–2.36)) compared to 1914. Mothers who were heavily exposed to the influenza pandemic during pregnancy had a higher risk of stillbirth (OR 2.27 (95% CI 1.32–3.9)). This study demonstrated that factors influencing neonatal health are multifactorial but similar in both time periods. Moreover, the exposure to the 1918/19 pandemic was less associated with LBW and more associated with an increased risk of stillbirth. If this trend is confirmed by further studies, it could indicate some consistency across pandemics, as similar patterns have recently been shown for COVID-19.

Between 1870 and 1930, all documented indicators of wellbeing and prosperity in the canton of Bern and in Switzerland in general showed a clear improvement, temporarily interrupted only by the first world war (in which Switzerland was not directly involved) and the influenza pandemic in 1918 [3]. Regarding GDP per capita, the canton Bern ranked 20th out of 25 cantons in 1880 and improved to 17th out of 25 in 1920 [64]. In this phase of increasing wealth, marked population growth occurred (from 478,364 in 1880 to 615,916 in 1920), and the degree of urbanization increased as well. In Bern, as elsewhere in Switzerland, due to a first step of globalization in the 1870s in the course of the coupling of the Swiss railroad network to the worldwide transport network, the cheap mass import of food became possible. The fact that from the 1870s onward prices stabilized while wages continued to rise led to an increase in the standard of living for the population overall. The improvement in real income was associated with a decline in the importance of food expenditures in the household budget. In 1830-1875, a working-class family in Switzerland spent approximately 62 percent of its budget on food, while at the beginning of the 20th century, food accounted for 40-50 percent of the total expenditure, and by 1950, it had fallen to 33 percent [4].
Not only do all monetary indicators of living standards trend upward in the canton of Bern for the period under study , but health and demographic indicators trend in the same direction; specifically, life expectancy has increased, infant and child mortality rates have fallen sharply, and the average adult height has increased. In addition to an improved nutritional status of the population, improvements in sanitary conditions and hygiene (e.g., WASH, clean and waste water supply), discourses about hygiene and nutrition, and better social welfare are often listed among the reasons, together with improved housing conditions. This is also reflected in the ongoing epidemiological transition, as the burden of infectious diseases has been greatly reduced during this period [5] The proportion of women in the labor force relative to the total female population in the canton of Bern slightly increased from 23.9% in 1880 to 25.9% in 1920 (the respective numbers for men were 60.2% and 64.6%) [66]. The sectoral distribution of working women underwent a significant change between 1880 and 1920; specifically, while 44.3% of working women were still employed in the agricultural sector in 1880 (compared with 39.7% in industry and 16.0% in the service sector), the proportion of working women in the service sector in particular doubled until 1920 (32.6%, compared with only 22.2% left in agriculture and 45.2% in industry) (S1 Table). There were striking differences between urban and rural areas and between the centers and the periphery. These shifts reflect the ongoing industrial transition that brought a decline in self-sufficient familyscale farming, as well as the creation of new options for paid work outside the home (e.g., industrialized textile industry and domestic services). However, the proportion of housewives among adult women was high at the beginning of the 20th century, which may have had an effect on the offspring's health outcome due to the accompanying emphasis on motherhood, which seemed to have triggered better attention and improved maternal care during pregnancy and the offspring's infancy (e.g., introduction of reduced working hours for women) [6]. 2 At the beginning of the 20th century, the First World War and especially the years 1917 to 1919 resulted in a marked interruption of the growing prosperity, and the influenza pandemic of 1918 and 1919 aggravated the situation. Although neutral Switzerland was spared military attacks during World War I, it was still severely affected by the length of the war and, in particular, by the Allied blockade and the resulting economic and social difficulties [7]. Switzerland particularly suffered because of its dependency on imports of grain and raw materials [8]. Toward the end of the war, food consumption in Switzerland had fallen to three quarters of its prewar level, and by 1917, the Swiss had approximately 25-30 percent fewer calories at their disposal than before the war. In the city of Bern, the proportion of the total household budget spent on food rose considerably in working-class families as well as in families of civil servants and employees. In working-class families, it increased from 46.9 percent in 1912 to 54.1 percent in 1919, and in families of civil servants and employees, the increase was even somewhat greater (32.4 percent had to be spent on food in 1912, compared with 38.4 percent in 1919). The fact that the food shortage was not as severe as in the warring neighboring countries is probably due in part to the relatively long and artificially low-kept milk price. Milk was the least expensive of all basic foodstuffs. During the first years of the war, milk consumption was still 19 percent higher than that in a normal year and even increased until 1916.
Anthropometric information on the birth weight of newborns in the city of Basel, on the growth monitoring of Bernese schoolchildren and on the body shape of conscripts during enlistment shows that the human body in Switzerland certainly reflected the increasingly deteriorated nutritional situation at the end of the First World War [4]. In the sense of interactions between nutritional status and immune status, the influenza pandemic exacerbated the situation in July/August (wave 1) and from October 1918 (waves 2 and 3). The canton of Berne was hit hard, albeit with regional differences (the cities had particularly high incidences and mortality rates) [1]. The course of the 1918 pandemic in the canton and the city of Bern is displayed in S1 Fig.

The maternity hospital in Bern
The cantonal maternity hospital in the city of Bern ("Frauenspital" or "Kantonale Entbindungs-und Frauenkrankenanstalt") was founded in 1875 [8]. Until the second half of the 19th century, maternity hospitals in general served only to admit women in childbirth. In the 19th century, women from lower socioeconomic positions were hospitalized to give birth because their housing situation did not offer good conditions for childbirth. The wealthier women usually preferred and could afford a home birth and midwives. Because hygiene conditions in hospitals were not favorable until the beginning of the 20th century, hospital births tended to be avoided. However, maternity hospitals underwent a change at the end of the 19th century [9]. With the increasing safety of hospitals and hospital births, the proportion of hospital births compared with home births rose significantly at the beginning of the 20th century. Maternity hospitals in general transformed markedly with the rise of obstetrical and gynecological sciences, together with broad improvements in midwifery. In addition to providing medical care, the maternity hospital of Bern also served as a training hospital for the university and as a midwifery school [9]. In approximately 1915, the maternity hospital of Bern represented the most important gynecological center in the Bernese midland region, and the increasing demand for hospital births and population growth in general triggered an extension of the existing building in 1919.
In S2 Table, a comparison of children born in the Bern maternity hospital (aggregated from the individual hospital data) with all children born in the city and canton of Bern between 1880 and 1925 shows that the relative proportion of all births in the city of Bern that occurred in the maternity hospital increased by 10 percentage points between 1899 and 1901 (from 13.7% to 24.8%) and then stabilized at approximately 20% until around 1908. Then, the proportion of hospital births began to rise significantly to >40% at the start of WW1.During WW1, there was another marked increase in the rate of hospital births, and after WW1, the hospital birth proportion constantly exceeded 50%. If the number of births in the entire canton of Bern is taken as a comparison, the proportions are of course smaller, but the pattern of temporal change is the same. 4 Tables and Figures S1